A daily dose of drugs made by Gilead Sciences Inc. (GILD) to treat HIV helped prevent infection in two studies that bolster earlier research showing existing medication can work to keep the disease from spreading.
The newest data, reported yesterday from trials undertaken in Africa, showed that those who used the Gilead drugs -- including uninfected people with partners who have HIV, and healthy heterosexual individuals -- had a much lower risk of infection than those on placebos.
The findings support conclusions of a study last year that showed Gilead’s Truvada, a $12,000-a-year drug, cut transmission of HIV in gay men. A separate trial in May found that treating the disease earlier than guidelines suggest reduces the risk to sexual partners. In total, the research suggests use of pre- exposure prophylaxis can stop the cycle of infection that affected the lives of 2.5 million people with newly diagnosed cases in 2009, according to United Nations data.
“On all fronts there are new, highly effective approaches for prevention,” including use of existing drugs, clean needles for injection drug users, male circumcision and vaginal gels, said Robert Grant, an associate professor at the Gladstone Institute of Virology and Immunology at the University of California, San Francisco. “These new opportunities demonstrate that we can win the war on HIV, if we act now.”
Proof the drugs inhibit HIV may bring more people in to get tested, and could mean that people who are newly infected and unaware would be less likely to spread the disease, Grant said in a statement.
Drop in Infections
The number of people who were infected with the Human Immunodeficiency Virus that causes AIDS in 2009 was about 21 percent less than in 1997, when annual infections peaked at about 3.2 million, UNAIDS said in a report last year.
Still, only 36 percent of 15 million people who need treatment in developing countries in Africa and Asia get it, the report said, and the latest findings could renew debate about the best way to use the potent drugs, particularly in poor countries where access to treatment is scarce.
Gilead fell 34 cents to $41.27 at 4 p.m. in New York time in Nasdaq Stock Market trading. The stock has gained 19 percent in the past year.
A study taking place in Kenya and Uganda, run by the University of Washington, was halted early after a safety board concluded it was unethical to continue the trial. People receiving Truvada, AIDS drugs sold by Foster City, California- based Gilead, were 73 percent less likely to contract HIV than those getting a placebo, according to the report yesterday.
All of the subjects were given counseling about HIV prevention, as well as condoms and regular HIV testing.
1,200 Heterosexual Volunteers
The second study, dubbed TDF2, was conducted in Botswana and funded by the U.S. Centers for Disease Control and Prevention. That trial, to be presented at the International AIDS Society meeting in Rome next week, involved 1,200 heterosexual volunteers who didn’t have HIV infections.
Nine patients taking Truvada contracted HIV during the study, compared with 24 patients given a placebo. The results show a 63 percent reduction in risk, the researchers said. Among those with consistent access to their drugs, the risk was even lower at 78 percent, they said.
“We now have findings from two studies showing that PrEP can work for heterosexuals, the population hardest hit by HIV worldwide,” said Kevin Fenton, director of the CDC’s national Center for HIV/AIDS.
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